Sodium and bromine would form an ionic bond. The one valence electron from sodium would be transferred to the bromine atom in order to obtain octet for both.
Ionic bond is a type of chemical bond and binds the chemical molecules together. Ionic bond is formed by the transfer of electrons from an electropositive element ( metal) to the electronegative element (non metal).
Sodium is an electropositive element and contains one positive charge. Bromine is an electronegative element with a single negative charge over it. Sodium gives the electron to bromine and results in the formation of ionic bond.
The amount of uranium within nuclear fuel rods is enough to sustain a chain reaction but is less than the critical mass necessary for the reaction to become explosive.
